Switching from Fluvoxamine to Fluoxetine

Key Considerations for Switching

The American Academy of Child and Adolescent Psychiatry recommends a conservative cross-tapering approach when switching from fluvoxamine to fluoxetine to minimize withdrawal symptoms and avoid serotonin syndrome, as fluoxetine has a very long half-life compared to fluvoxamine 1
Fluvoxamine has been associated with discontinuation syndrome and should be tapered slowly, according to the American Academy of Child and Adolescent Psychiatry 2, 1
Both medications are SSRIs with potential for serotonin syndrome if not switched properly, as noted by the American Academy of Child and Adolescent Psychiatry 3, 1
Fluoxetine may be more activating than fluvoxamine, which can affect initial dosing, as reported in the American family physician 4

The American Academy of Child and Adolescent Psychiatry suggests reviewing potential drug interactions as fluvoxamine has greater potential for drug-drug interactions via multiple CYP450 pathways 2, 1
The recommended cross-tapering schedule is to reduce fluvoxamine by 25% of original dose while starting fluoxetine at 10mg every other day in Week 1, as recommended by the American family physician and the American Academy of Child and Adolescent Psychiatry 4, 1

The American Academy of Child and Adolescent Psychiatry recommends monitoring closely for signs of serotonin syndrome during the first 24-48 hours after each dosage change 2
The American Academy of Child and Adolescent Psychiatry suggests watching for withdrawal symptoms from fluvoxamine, such as dizziness, fatigue, headaches, nausea, sensory disturbances, and anxiety 1
The American family physician notes that fluoxetine's side effects may not manifest for a few weeks due to its long half-life 4
The American family physician recommends starting fluoxetine at a low dose (10mg) as it can be activating and may initially increase anxiety 4, 1
The typical effective dose of fluoxetine is 20mg daily, compared to 100-150mg daily for fluvoxamine, as reported in the American family physician 4

The American Academy of Child and Adolescent Psychiatry warns that never abruptly switching between SSRIs can lead to serotonin syndrome, and always using cross-tapering can avoid this potentially life-threatening condition 2, 3
The American Academy of Child and Adolescent Psychiatry notes that fluvoxamine has a shorter half-life than fluoxetine and can cause withdrawal symptoms if discontinued too quickly 1
The American Academy of Child and Adolescent Psychiatry suggests being aware that fluoxetine inhibits CYP2D6, while fluvoxamine affects multiple CYP enzymes (CYP1A2, CYP2C19, CYP2C9, CYP3A4, CYP2D6) 2, 1

The American Academy of Pediatrics recommends following up within 1-2 weeks after completing the switch and assessing for both therapeutic response and adverse effects 5
The American family physician and the American Academy of Child and Adolescent Psychiatry suggest monitoring for up to 4-6 weeks to ensure stabilization on fluoxetine 4, 1